(1) All so-called "pure" preparations of the blowfly protein calliphorin, both from this and other laboratories, are composites of two or three closely similar proteins. (2) Blowfly fat body in organ culture liberates labeled proteins, including calliphorin, into the medium. Labeled calliphorin is being prepared from this source. (3) The in vitro synthesis of calliphorin appears to be inhibited by the molting hormone ecdysone. (4) The rates of ribosomal RNA degradation and synthesis during fly metamorphosis have been revised. Ribosomes of the adult fly are almost entirely made de novo. (5) Granular hemocytes (phagocytes) have been isolated and maintained in cell culture. These cells in vitro engulf a variety of foreign particles. (6) A unique natural compound isolated from the male accessory glands of Drosophila melanogaster has been characterized as 4(1-beta-galactopyranosyl-X-glycerol) phosphoethanolamine. of the v